Elastomer-reinforced polymers of monovinylidene aromatic compounds such as styrene, alpha-methylstyrene and ring-substituted styrene have found widespread commercial use. For example, elastomer-reinforced styrene polymers having discrete elastomer particles such as cross-linked rubber dispersed throughout the styrene polymer matrix can be useful for a range of applications including food packaging, office supplies, point-of-purchase signs and displays, housewares and consumer goods, building insulation and cosmetics packaging. Such elastomer-reinforced polymers are commonly referred to as high impact polystyrene (HIPS).
Methods for the production of polymers, such as HIPS, typically employ polymerization using a continuous flow process. Continuous flow processes may involve a plurality of serially arranged reaction vessels wherein the degree of polymerization increases from one vessel to the next. Factors such as the arrangement of the reaction vessels and the reaction conditions influence the characteristics of HIPS produced. Different grades of HIPS may have differing elastomer content and extents of polymerization within each reactor resulting in differing mechanical and/or optical properties.
Key costs for the production of HIPS are associated with the type of continuous flow process used and the amount of elastomer utilized. Thus it would be desirable to develop an apparatus and methodology for the production of HIPS having a reduced elastomer content with enhanced mechanical properties.